Added HTTP example

Need to work on improving the HTTP API to make it more consistent and features.

Author: Tyler Cloutier

README.md

@@ -46,6 +46,44 @@ let package = Package(
 
 # Usage
 
+### HTTP
+```swift
+import Edge
+import Foundation
+
+func handleRequest(request: Request) -> Response {
+    print(String(bytes: request.body, encoding: .utf8)!)
+    let responseBodyObject = ["message": "Message received!"]
+    let responseBody = Array(try! JSONSerialization.data(withJSONObject: responseBodyObject))
+
+    return Response(
+        version: Version(major: 1, minor: 1),
+        status: .ok,
+        rawHeaders: ["Content-Type: application/json"],
+        body: responseBody
+    )
+}
+
+let server = HTTP.Server()
+server.listen(host: "0.0.0.0", port: 3000).startWithNext { client in
+
+    let requestStream = client.read()
+    requestStream.map(transform: handleRequest).onNext{ response in
+        client.write(response)
+    }
+
+    requestStream.onFailed { clientError in
+        print("Oh no, there was an error! \(clientError)")
+    }
+
+    requestStream.onCompleted {
+        print("Goodbye \(client)!")
+    }
+
+    requestStream.start()
+}
+```
+
 ### TCP
 ```Swift